The Harvard-MIT MD-PhD Program provides an integrated approach to educating physician-scientists to become leaders in American medicine and biomedical research. In this program, students combine medical studies at Harvard Medical School with graduate studies at Harvard or MIT. The program offers students arguably the largest selection of academic laboratories in the world for research training, complemented by outstanding teaching hospitals that are poised to rapidly translate basic discoveries into new clinical applications. Students choose between two medical education curricula: a case based approach that combines small-group teaching and problem-oriented learning with more traditional teaching methods (New Pathway), or a traditional curriculum with an emphasis on quantitative analysis and technology (Health Sciences and Technology). Both curricula include rigorous clinical clerkships at the Harvard teaching hospitals. Students also choose from among the four graduate programs in the Division of Medical Sciences at Harvard Medical School, other graduate programs in the Harvard Graduate School of Arts and Sciences, and programs in the Graduate Schools of Science and Engineering at MIT. The medical and scientific training components are integrated throughout the program, beginning with a course in the Molecular Biology of Human Disease and a laboratory research rotation that are taken by all MSTP students during the summer before the first academic year. Although not all MD-PhD students are awarded funding at the time of matriculation, the program is designed to include all students at Harvard Medical School who are simultaneously pursuing the MD and PhD degrees. Unfunded students can enter the program at the time of enrollment in a PhD program. The program provides academic and mentoring support to approximately 148 students, taking advantage of a large, committed faculty. Approximately faculty members are directly involved with the program through service on program committees and/or participation as MD-PhD student thesis advisors. Mentoring, advising, and all program activities are available both to students who are funded by MSTP and to students who are not. Other training grants, individual NIH investigator (R01) awards, individual student fellowships, departmental funds, hospital funds and unrestricted institutional funds are used to supplement MSTP student support.